/*
 * [New BSD License]
 * Copyright (c) 2011-2012, Brackit Project Team <info@brackit.org>  
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Brackit Project Team nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.brackit.xquery.operator;

import java.io.PrintStream;

import org.brackit.xquery.QueryContext;
import org.brackit.xquery.QueryException;
import org.brackit.xquery.Tuple;
import org.brackit.xquery.operator.Cursor;
import org.brackit.xquery.xdm.Sequence;

/**
 * 
 * @author Sebastian Baechle
 * 
 */
public class TuplePrintOp implements Cursor {
	private final Cursor in;

	private final PrintStream out;

	private int maxSize = 20;

	private int count;

	public TuplePrintOp(Cursor in, PrintStream out) {
		this.in = in;
		this.out = out;
	}

	@Override
	public void close(QueryContext ctx) {
		in.close(ctx);
		out.println("---");
		out.print(count);
		out.println(" results");
	}

	@Override
	public Tuple next(QueryContext ctx) throws QueryException {
		Tuple next = in.next(ctx);
		if (next != null) {
			count++;
			int size = next.getSize();
			out.print("|");
			for (int i = 0; i < size; i++) {
				out.print(' ');
				Sequence sequence = next.get(i);
				String s = asString(ctx, sequence);
				s = shrinkOrPad(s);
				out.print(s);
				out.print(" |");
			}
			out.print('\n');
		}
		return next;
	}

	public String asString(QueryContext ctx, Sequence sequence) {
		return sequence.toString();
	}

	private String shrinkOrPad(String s) {
		int length = s.length();

		if (length == maxSize) {
			return s;
		}
		if (length > maxSize) {
			return s.substring(0, maxSize);
		}

		int toAdd = (maxSize - length);
		char[] result = new char[maxSize];

		int i = 0;
		while (i < (toAdd / 2)) {
			result[i++] = ' ';
		}
		System.arraycopy(s.toCharArray(), 0, result, i, length);
		int j = i + length;
		while (i++ < toAdd) {
			result[j++] = ' ';
		}
		return new String(result);

	}

	@Override
	public void open(QueryContext ctx) throws QueryException {
		in.open(ctx);
		count = 0;
	}
}
